61 



One well acquainted with wheat varieties i.s usually able to determine 

 largely their general classification simply from their appearance in the 

 autumn. 



It will be seen also by a stud}^ of the table that there is a very close 

 constant relation between hardiness, color, size, weight, and hardness 

 of grain, and chemical composition in varieties of the common group. 

 Varieties very resistant to cold and drought have small, hard, red 

 grains, possessing a large proportion of albuminoids and a relatively 

 high specitic gravity, though the absolute weight is likely to be low. 

 It is also a general rule that bearded varieties are less susceptible to 

 leaf rust, l)ut there are a number of important exceptions to this rule. 

 Varieties with harsh, hairy, or glaucous leaves are also usually rather 

 resistant to this rust. Varieties early in ripening are often dwarfed, 

 and come from warm regions nearly always. Hard-grained winter 

 varieties are bearded, as a rule. Drought resistant sorts, whether 

 bald or bearded, white or red-grained, possess a larger proportion of 

 nitrogen than those which succumb to drought. 



The effect of a change of environment upon the wheat plant has 

 already been referred to. That marked changes are effected in this 

 way is proved, with respect to chemical composition, by the facts 

 given in the table. In a number of instances duplicate analyses are 

 given of samples of the same variety obtained from different localities. 

 Almost invariably the samples from hot and more or less arid dis- 

 tricts show a larger per cent of gluten content. In some instances the 

 difference is considerable. Alsace wheat from Ekaterinoslav (Russia) 

 furnishes 13.. 58 per cent of dry gluten, while the same variety from 

 Poltava, farther northwest in a moister region, shows only 9.30 per cent. 

 Improved Fife, though a much liked variety in Australia, produces 

 but 11.20 per cent of gluten there in comparison with 16.16 per cent 

 in Colorado. Kubanka from Kursk (Russia) possesses 37.79 per 

 cent moist gluten and 13.63 per cent of dry gluten, while as grown in 

 Germany it furnishes only 20.93 per cent of moist gluten and 8.50 per 

 cent of dry gluten. At the same time a sample from the Caucasus 

 shows 41.65 per cent of moist gluten. A remarkable difference is 

 shown in the ease of Scotch Fife from Nel)raska and Oregon. The 

 former sample contained 14.65 per cent of dry gluten, while the latter 

 contained onh^ 5.13 per cent, slightly over one-third as much. There 

 is a striking example in the case of Palouse Blue Stem of a differ- 

 ence in gluten content between two samples from the same Stiite, 

 Washington. These samples, however, were no doubt from diffiMcnt 

 localities, and no two regions are likely to be much more different from 

 each other than are western Washington and the Palouse country of 

 eastern Washington. 



A most interesting example of correspondence between climate and 

 chemical composition of the grain is exhibited in the case of samples 



